JP 2012-202230A (US 2012/240901 A1) describes a suction filter which is arranged in a fuel tank of a vehicle.
The suction filter has a filter material and a fuel passage space located on an inner side of the filter material. The fuel passage space is located higher than an intake port of a fuel pump. If fuel sufficiently permeates the filter material to form a fuel (oil) film, air stays in the higher part in the fuel passage space. Further, for example, in case where the vehicle is inclined by a quick turn, if the fuel surface in the suction filter is inclined, much air is rapidly drawn into the intake port. At this time, the fuel pump cannot achieve sufficient fuel discharge performance.